build: add Docker multi-stage build with nginx

docker/Dockerfile

@@ -0,0 +1,31 @@
+FROM node:24-alpine AS builder
+
+WORKDIR /app
+
+COPY package*.json ./
+
+RUN npm clean-install --verbose
+
+COPY . .
+
+RUN npm run build --verbose
+
+FROM nginx:stable-alpine
+
+RUN apk add --no-cache curl
+
+RUN rm -rf /usr/share/nginx/html/*
+
+COPY --from=builder /app/dist /usr/share/nginx/html
+
+COPY ./config/nginx/nginx.conf /etc/nginx/conf.d/default.conf
+
+RUN chown -R nginx:nginx /usr/share/nginx/html && \
+    chmod -R 755 /usr/share/nginx/html
+
+EXPOSE 80
+
+HEALTHCHECK --interval=30s --timeout=3s \
+    CMD curl -f http://localhost/ || exit 1
+
+CMD ["nginx", "-g", "daemon off;"]